# Functions
NewAPID creates new instance of APID backend.
NewAPIDFactory creates new APIDFactory with given tls.Config.
# Constants
GracefulShutdownTimeout is the timeout for graceful shutdown of the backend connection.
# Structs
APID backend performs proxying to another apid instance.
APIDFactory caches connection to apid instances by target.
# Interfaces
TLSConfigProvider provides tls.Config for client connections.